Choose side mount when the side space fits
A practical option for an existing compatible drawer or a new box designed around side-mounted rails. The slides remain visible along the drawer sides when open.
Compare the side-mount kitSide Mount vs Undermount Drawer Slides
Side-mount slides attach beside the drawer; undermount slides support it from below. Choose by the drawer box you have or plan to build, the hardware visibility you want, and the requirements of the exact slide model—not by a blanket assumption that one mounting style is stronger.
Choose undermount for clear drawer sides
Choose concealed rails when appearance matters and you can match the drawer width, side thickness, bottom recess and rear preparation to the selected system.
Compare the undermount kitSoft close is a separate feature. Either mounting style can offer damped closing. Both Berta kits featured here include it.
At a glance
What is the difference between side-mount and undermount slides?
Mount position affects the drawer design. Closing action, travel and load rating are separate specifications to verify.
On a small screen, swipe across the table to compare both columns.
| Feature | Side-mount slides | Undermount slides |
|---|---|---|
| Mounting position | On the drawer sides and inside the cabinet. | Beneath the drawer box, using a compatible support and locking system. |
| Appearance | Rails are visible beside the open drawer. | Drawer sides are unobstructed by rails; hardware is concealed underneath. |
| Drawer-box fit | Requires the specified side clearance, mounting height and suitable fixing surfaces. | Requires model-specific width, side thickness, bottom recess and back preparation. |
| Replacing existing slides | Can simplify a like-for-like replacement when all measurements match. | Changing from side mount can require a different or modified drawer box. |
| Soft close | Available on some models; included on the featured side-mount kit. | Available on some models; included on the featured undermount kit. |
| Load capacity | Model-specific. Featured Berta side-mount listing: up to 100 lb per pair. | Model-specific. Featured Berta undermount listing: up to 100 lb per pair. |
| Extension / access | Check travel separately from mount type. The featured side-mount model is full extension. | Mount position alone does not specify travel; confirm the selected model’s extension. |
| Best selection basis | A drawer built for the slide’s side space, with visible rails acceptable. | A compatible drawer designed for concealed support, locks and the required clearances. |
Shop the comparison
Compare side-mount and undermount soft-close kits
Both options below include soft close, so the key decision is drawer fit and where the hardware mounts. An 18-inch option is selected for each when available in the catalog; always confirm the displayed size and its installation requirements.
View current product photos and options
Soft close · 10-pair package
View Side-Mount Slides
Full Extension Soft-Close Side-Mount Slides
Ball-bearing side-mount slides for drawers built with the required side space. Full-extension travel and damped closing.
- Mounting
- Side mount
- Closing action
- Soft close
- Listed load rating
- Up to 100 lb per pair
- Included hardware
- Face-frame brackets + screws
Selected option: 18 Inch
Listed kit: 10 pairs / 20 slides. One matched pair supports one drawer.
Price for the selected 10-pair kit$130.56 USD
Available to order · Confirm fulfillment on the product page
View current product photos and options
Soft close · 10-pair package
View Undermount Slides
Soft-Close Undermount Drawer Slide Kit
Concealed rails for a compatible drawer box, with front locking devices and rear brackets included in the listed kit.
- Mounting
- Under the drawer
- Closing action
- Soft close
- Listed load rating
- Up to 100 lb per pair
- Included hardware
- Locking clips, rear brackets + screws
Selected option: 18 inch
Listed kit: 10 pairs / 20 slides. One matched pair supports one drawer.
Price for the selected 10-pair kit$184.99 USD
Available to order · Confirm fulfillment on the product pagePhotos and prices come from Shopify. Confirm your selected option and package contents before ordering. Shipping, taxes and any eligible discounts are finalized at checkout.
Compare the same length and package size. Both featured product listings specify up to 100 lb per pair; that does not make the drawer construction or mounting requirements interchangeable. Use the exact model’s rating and instructions for your project.
Understand the hardware
How the two drawer systems are installed
What are side-mount drawer slides?
These slides connect the drawer sides to mounting surfaces inside the cabinet. Ball-bearing designs are common. Their location makes the rail hardware visible and makes the available space beside the drawer a key measurement.
A familiar mounting style is not a universal fit: check the slide thickness, required side space, depth, fixing locations and any brackets needed for your cabinet.
What are undermount drawer slides?
These slides sit under the drawer box. Systems such as the featured Berta kit use front locking devices and rear engagement points, so the drawer must be prepared for that hardware.
Check the bottom recess, side thickness, drawer width and length, plus the back notches and hook holes specified by the system. Do not copy cutting dimensions from a different slide brand.
Before you order
Before switching from side mount to undermount
Measure the existing drawer and cabinet before buying replacement slides. Matching the nominal length alone is not enough.
- 1. Cabinet opening & depthMeasure the clear opening and usable depth. Account for the face frame, door or hinge protrusion, plumbing and rear brackets.
- 2. Drawer width & side spaceRecord the outside drawer width and the available space on each side. Use the selected model’s width formula—not a generic deduction.
- 3. Side thickness & bottom recessUndermount systems need room for their rails and locks. Check both the drawer-wall thickness and where the bottom sits.
- 4. Back notches, holes & locksVerify rear-hook engagement and front-lock placement. Existing drawer joinery may prevent a straightforward conversion.
- 5. Nominal size vs actual drawer lengthUse the model’s dimensional drawing to set the box length. An 18-inch label is not a universal instruction to cut an 18-inch box.
- 6. Loaded drawer & mountingCheck drawer weight plus intended contents, drawer dimensions and the specified fasteners. A pair rating is not a rating for each rail.
Do not turn a side-mount slide flat and assume it becomes an undermount. Only use an orientation explicitly approved for that exact model. Mounting orientation can reduce rated capacity or affect operation. Technical reference.
Berta installation support
Plan the drawer around the chosen undermount system
Our walkthrough covers drawer preparation, locking devices, cabinet mounting and adjustment. Use the guide together with the current instructions for the exact kit you order.
Building new drawers?
Choose the hardware before finalizing the cut list. This lets you design the drawer around the required clearances rather than alter a finished box.
Keeping the existing boxes?
Check whether their dimensions and joinery meet the replacement system’s requirements. A compatible side-mount replacement may avoid rebuilding; concealed rails may need changes.
Common questions
Side-mount vs undermount drawer slide FAQs
Are undermount drawer slides better than side-mount slides?
They are the better match when you want concealed hardware and the drawer can meet the system’s design requirements. Side mount remains useful when visible rails are acceptable and the drawer has the specified side space. Choose the fit, closing action and rating your project needs.
Can I replace side-mount slides with undermount slides?
Sometimes, but not as a guaranteed drop-in change. Compare drawer width, bottom position, side thickness, length and back preparation. A new drawer box may be necessary when the existing one cannot accommodate the locks, hooks or clearances.
Are side-mount slides always stronger?
No. Compare the ratings for the actual models and their installation conditions. The two featured Berta listings both specify up to 100 lb per pair. Equal published ratings are not an independent test of identical performance.
Can I mount side-mount slides under the drawer?
Not unless the manufacturer expressly approves that orientation for the model and provides an applicable rating. A purpose-built undermount system and a side-mount rail turned flat are not the same design.
Do all undermount slides have soft close?
Do not assume that from the mounting position. Check the product specification. Soft close controls the final closing movement; side mount and undermount describe where the hardware is installed.
Does the slide length have to equal the drawer-box length?
Follow the exact model’s dimensional instructions. Required box length can differ from the nominal slide size, and usable cabinet depth must also allow for the mounting system.
How many drawers does a 10-pair kit cover?
A matched left-and-right pair supports one compatible drawer, so ten pairs provide slide hardware for ten drawers. Confirm the kit contents, selected size and any project-specific mounting needs before ordering.
Can these slides be used in face-frame cabinets?
Check the model’s supported installation and bracket requirements. The listed kits include mounting hardware, but a face frame, rear support or other obstruction can still affect fit. The Berta undermount guide covers framed and frameless installation arrangements.
Choose the slide before cutting the drawer.
Have the cabinet opening, usable depth, drawer dimensions and intended load ready. Berta Store can help you compare the correct mounting system.
Product specifications and technical references
Featured specifications are from the Berta side-mount kit and Berta undermount kit. Prices and availability are supplied by Shopify; follow current product instructions for actual installation.
The Berta installation guide supplies system-specific preparation steps. Accuride’s slide-mounting explanation supports the general caution about mounting orientation; it is not a compatibility approval or rating for Berta products.